A device using silicon carbide (SiC), for example, has received attention as a low-loss semiconductor device which can be operated under high temperature. Silicon carbide (SiC) has excellent physical properties such as a band gap being three times that of silicon (Si), breakdown electric field strength being approximately ten times that of silicon, and thermal conductivity being approximately three times that of silicon. It is desired, in such semiconductor device, that an electrode to be connected to an electric circuit or the like establish an ohmic contact. A high avalanche breakdown voltage can be obtained by a low on-state resistance and excellent well potential control when the electrode establishes a satisfactory ohmic contact.